Grease composition



United States Patent ,5 0 GREASE COMPOSITION Keith Conpland, Hornsea, England, assignor to BP Chemicals (U.K.) Limited, London, England, a British company No Drawing. Filed Oct. 4, 1967, Ser. No. 672,693 Claims priority, application Great Britain, Oct. 29, 1966,

Int. Cl. C10m 7/44 US. Cl. 25242.1 5 Claims ABSTRACT or m: DISCLOSURE The invention is a grease composition suitable for use under extreme pressure conditions comprising a base fluid, an alkali metal salt of a fatty acid and a tris-(2- chloroalkyl) ester of an oxyacid of phosphorus.

The present invention relates to grease compositions suitabl for use under extreme pressure conditions.

According to the invention, a grease composition suitable for use' under extreme pressure conditions comprises a base fluid, an alkali metal salt of a fatty acid and a tris-(Z-chlciroalkyl) ester of an oxyacidof phosphorus.

The base fluid is suitably a hydrocarbon orprefeiably an ester which may be used as a synthetic lubricant base. Examples include esters of polyhydroxy compounds, such as trimethylol propane tricapryla'te, and esters of polycarboxylic acids such as dinonyl sebacate. Other examples are; the 222:6:6-tet1'akis alkyl-cyclohexanone-flpropionate, 2: 2: 5: S-tetrakis alkyl-cyclopentononeqp-propionate, 2-alkyl-2z6z6-tris-alkyl cyclohexanone '18 propionate and 2 alkyl 2:5:S-tris-alkyl-cyclopentanonefl-propionate esters whose use as lubricant bases is disclosed in British patent specification 1,036,692.

The alkali metal salt, which is preferably the lithium salt, acts as a thickener and may be, for example, the palmitate, oleate, l2-hydroxystearate or preferably the stearate. It should comprise from 5 to 3 0% by weight, preferably 10-20% of the composition.

Examples of suitable tris-(2-chloroalkyl) esters of the oxyacids of phosphorus are tris-(2-chloroethyl) and tris- (2-chloropropyl) phosphite, and also the corresponding phosphate ester. The concentration of the ester in the composition should be in the range 0.1-5.0% by weight preferably 0.52%

The compositions may also contain conventional grease additives such as antioxidants and rust and corrosion inhibitors.

The greases may be prepared by heating together the ester lubricant and alkali metal salt while stirring until a clear solution is obtained. The solution is cooled rapidly to give a gel which is worked to give the desired grease.

The grease may also conveniently be prepared by generating the alkali metal salt in situ by addition of the fatty acid and saponifying it with alkali metal hydroxide, the removal of water. The ester of the oxyacid of phosphorus may be included at any stage of manuafacture but for convenience and to avoid undesirable interaction at high temperature they are conveniently included at the cold working stage. The cold working procedure involves milling or mixing at high shear rates to give a grease of smooth appearance.

The grease formulations are further illustrated in the following examples.

'3 EXAMPLE 1 A mixture of lithium stearate (10 parts) and dinonyl sebacate parts) was heated with stirring to 140? C. and held at this temperature for 1 hour. The temperature was then raised to-l85 C. and the resulting solution cooled rapidly to give a gel. The cooled gel was worked in "a'high shear mixer until a grease of smooth appearance resulted.

EXAMPLE 2 The procedure of Example 1 was followed using the same proportions but tris-(Z-chloroethyl) phosphite (1 part) was milled in at the cold working stage.

EXAMPLE 3 As for Example 2 substituting tris-(2-chloropropy1) phosphite (1 part) as extreme pressure agent.

1 EXAMPLE 4 As. for Example 1 substituting trimethylol propane tricaprylate as the ester lubricant.

EXAMPLE 5 As for Example 4 with the addition of tris-(2-chloroethyl) phosphite (1 part) as extreme pressure additive.

EXAMPLE 6 As for Example 4 with the addition of tris-(2-chloro' ethyl) phosphite (1 part) as extreme pressure additive.

EXAMPLE 7 As for Example 1 substituting 2:2:626-tetrakis butylcyclohexanone-beta-propionate as the ester lubricant.

EXAMPLE 8 As for Example 7 with the addition of tris-(2-chloroethyl) phosphite (1 part) as extreme pressure additive.

The results of extreme pressure tests using the above formulations are indicated in Table 1.

TABLE 1 10 see. Wear Scar Diameters (Shell Four Ball Test) (10% lithium stearate greases with EP additives at 1% concentration] Wear Sear diameter (111111.) EP additive (at Base Fluid Example 1% concentration) I 50 kg. 75 kg. kg.

1 None 345 2.23 2.24 2 Tris-(2-chloroethyl) 0 824 0.381 2.07 Dinonyl sebacate phosphite.

3 Tris-(2-chloropropyl) 0.350

phosphite. I 4 None 0.378 2. 06 3.29 Trillnhylol propane 5 Tgi-ggiglttr-oethyl) 0 355 0.830 2. 21 tmaprylm- 6 Tris-(2chloroethyl) 0 359 0. 575 2. 09

. phosphate. 2:2:6z6-tetrakis butyl- 7 None .324 0.506 2. 23 eyclohexanone beta- 8 Tris-(Z-ehloroethyl) 0 347 0.400 1. 96 propionate phosphite.

3 4 I claim: chloropropyl) phosphite, tris-(Z-chloroethyl) phosphate 1. A grease composition suitable for use under exor tris-(Z-chloropropyl) phosphate. treme pressure conditions comprising a synthetic base 7 fluid, from 5 to 30% by weight of the composition of r References Cited a lithium salt of a fatty acid selected from the groupcon- 5 UNI'TEDISTATES PATENTS sisting of stearic, palrnitic, oleic and hydroxystearic and V r 1 H a tris-(2-chloroalkyl) ester of an oxyacid of phosphorus 23945804 9/1942 Rlckett? 252421 comprising 0.1 to 5.0% by weight of the composition. 2872417 V 2/1959 7 Jordan 'et 252-424 2,929,785 3/1960' Morway et al. 25241 2. A grease compos tion according to clalm 1 wherein 2 999 066 79/1 61 V g the base fluid is trimethylol propane tricaprylate, 10 f y f-"f 252-39 3. A grease composition according to claim 1 wherein FOREIGN EATENTS the base fluid is dinonyl sebacate. W

4. A grease composition according to claim '1 wherein 1'036692 7/196? G Bummthe base fluid isx'selected from 2:2:6:6-tetrakis alkyl- OTHER REFERENCES cyclohexanone-B-propionate, 2:2:5z5-tetrakis alkyl-cyclo- 15 r! h pentanone-fl-propionate, 2-alkyl-2z6z6 tris-alkyl-cyclo- Extreme m Lubricants, by Davey, 111 u hexanone-g-propionate or 2-alkyl-2z5z5-tri's alkyl-cyc lomal and Engmeermg -a p l 5?, PP- 8 1- pentanone-fi-propionate. t I u 5. A grease compositionaccording to claim 1 wherein Z the tris-(Z-chloroalkyl) ester of an oxyacid o1 phosphorus 20 DANIEL WYMAN Pgmary Exammer is selected from tris-(Z-chloroethyi) phosphite, tris-(2- I. VAUGHN, Assistant Examiner 

